A horn, which vibrates a diaphragm with a movable iron core and outputs the sound generated by the diaphragm to the outside through a resonance tube, is mounted on a vehicle. Since the resonance tube has a spiral shape, there is a problem that foreign matter such as water cannot be removed if the foreign matter enters and accumulates in the resonance tube. Thus, PTL 1 discloses an electric horn for a vehicle, in which a foreign matter entry prevention member is affixed to a sound wave outlet opening portion of a resonance tube to prevent foreign matter flying from the front side of the vehicle from entering the resonance tube.